1. Field of the Invention
The present invention relates to an automatic spew trimming method, wherein spew or flash generated in the vulcanizing step can be cut off from external surfaces of various kinds of vulcanized tires. The present invention also relates to an apparatus used for the method.
2. Description of Related Art
Trimming of a vulcanized tire has been conventionally carried out in such a manner that a tire is independently rotated for example by two drive rollers and two guide rollers to be trimmed by a knife. In that case, the rollers are positioned at the outer circumference of the tire. Another conventional trimming is carried out in such a manner that a tire is assembled with a rim and is inflated, thereafter the tire is rotated by rotating the rim to trim the tire with a knife.
However, the above-mentioned two conventional trimming methods have drawbacks respectively. In the method where a tire is independently rotated to be trimmed by a knife, trimming of a low rigidity tire and a tire having much small tread width such as a motor cycle tire is impossible because smooth rotation of such tires is impossible. In this method, even if the apparatus is adjusted or modified, that is, roller pressure is changed or roller figure is specified for a certain tire, to enable the trimming of the tire, the apparatus must be for exclusive use of the very tire so that other kinds of tire can not be trimmed. In the method where a tire is assembled with a rim and is rotated, the rim must be changed depending on the rim diameter for tires of different rim diameter. Thus flexible operation can not be realized for different rim diameters.
In view of the drawbacks of the conventional methods, an object of the present invention is to provide a method for automatically trimming spew and an apparatus used therefor, wherein spew or flash generated in the vulcanizing step can be cut off from an external surface of a vulcanized tire in a single apparatus without parts replacement for many kinds of tires of different rigidity, tread width and size.